1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, systems, and products for acquiring test data from an electronic circuit.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
To continue the development of these powerful computer systems and maintain current computer systems, electronics technicians require powerful tools for testing electronic circuits. Testing is the analysis of defects in the operation of electronic circuits and the optimization of performance of electronic circuits. Testing electronic circuits often involves connecting oscilloscope to an electronic circuit board to enable the observation and characterization of the electronic signals of an electronic circuit of the electronic circuit board.
Testing electronic circuits with an oscilloscope, however, has certain disadvantages. To test electronic circuits through an electronics circuit board, an electronics technician may manually connect the oscilloscope to an electronic circuit board using oscilloscope probes. When an electronics technician manually holds oscilloscope probes against an electronic circuit board, unreliable measurements are often produced because of a poor connection between the oscilloscope probe and the electronic circuit board. In addition, manual probing may even be impossible when the electronic circuit board is located in a physically inaccessible area.
As an alternative to manual probing, an electronics technician may attach oscilloscope probes to an electronic circuit board using a ‘probe adapter.’ An electronics technician often manually solders the probe adapter to the electronic circuit board for testing. The oscilloscope probes then connect to the probe adapter through a receptacle. An electronic technician must create each probe adapter, map each probe adapter attachment point to the electronic circuit board from a schematic diagram of the electronic circuit board, and solder each probe adapter individually to the electronic circuit board. Creating, mapping, and soldering each probe adapter is time-consuming and conducive to error.
When an electronics technician establishes a connection between the oscilloscope and the circuit board, the physical size of each probe adapter relative to the footprints of most electronic components often allows for only a limited number of adapters to be simultaneously connected to a particular electronic component on an electronic circuit board. Often the number of adapters that can be simultaneously connected to a particular electronic component is far less than the number of electronic circuits that an electronics technician needs to simultaneously test. For example, a typical dynamic random access memory (‘DRAM’) module may require an electronics technician to test up to twenty electronic circuits, while physical limitations of the DRAM module may only allow an electronics technician to only place four probe adapters in the vicinity of the DRAM module.
Other problems testing electronic circuits with an oscilloscope and probe adapters also exist. Oscilloscopes are typically limited to a small number of channels, each channel capable of testing one electronic signal of an electronic circuit. An electronics technician must therefore move the oscilloscope probes many times in order to test a large number of electronic signals. Moving oscilloscope probes by engaging and disengaging the oscilloscope probes from a probe adapter produces mechanical stresses that may cause the connections between the oscilloscope probe, the probe adapter, and the electronic circuit board to fail. A failed connection may produce unreliable measurements of the electronic signal or not produce any measurements at all.
Additional problems when testing electronic circuits with oscilloscopes arise from the oscilloscope cable that connects the oscilloscope and the oscilloscope probes. Typical oscilloscope cables range from two to three feet and forces close proximity of the oscilloscope to the oscilloscope probes connected to the circuit board. Testing an electronic circuit board buried deep inside a computer chassis may be difficult or impossible when the distance between the oscilloscope and the electronic circuit board is greater than the length of the oscilloscope cables. When a connection is possible, parasitic electronic signals entering the oscilloscope cable from the debugging environment may cause degradation of the electronic signal under test.